1 00:00:11,900 --> 00:00:10,970 I am Ryan Loomis and I'm at the 2 00:00:13,430 --> 00:00:11,910 harvard-smithsonian Center for 3 00:00:15,829 --> 00:00:13,440 Astrophysics and I'm going to be talking 4 00:00:17,420 --> 00:00:15,839 today about uncovering dust substructure 5 00:00:19,400 --> 00:00:17,430 and chemical complexity and 6 00:00:22,689 --> 00:00:19,410 protoplanetary discs so thank you sunny 7 00:00:25,340 --> 00:00:22,699 for the the introduction there so 8 00:00:27,349 --> 00:00:25,350 basically what I want to talk about 9 00:00:29,150 --> 00:00:27,359 today is with protoplanetary discs 10 00:00:31,429 --> 00:00:29,160 there's there's two main things that are 11 00:00:33,290 --> 00:00:31,439 relevant for astrobiology the first is 12 00:00:35,299 --> 00:00:33,300 that as Sonny mentioned protoplanetary 13 00:00:38,000 --> 00:00:35,309 discs are kind of the middle stage in 14 00:00:39,709 --> 00:00:38,010 between when you start off from a cloud 15 00:00:42,049 --> 00:00:39,719 and then it starts to collapse down and 16 00:00:43,220 --> 00:00:42,059 form a star protoplanetary discs forms 17 00:00:45,020 --> 00:00:43,230 from the angular momentum of the 18 00:00:46,580 --> 00:00:45,030 material around the star and that's 19 00:00:48,170 --> 00:00:46,590 going to include all the material that 20 00:00:50,690 --> 00:00:48,180 eventually becomes planets comets 21 00:00:52,549 --> 00:00:50,700 everything in the solar system so 22 00:00:54,439 --> 00:00:52,559 anything that you care about in terms of 23 00:00:56,810 --> 00:00:54,449 exoplanets etc is coming from a 24 00:00:57,799 --> 00:00:56,820 protoplanetary disk so that's the first 25 00:00:59,270 --> 00:00:57,809 thing that I'm going to talk about is 26 00:01:00,560 --> 00:00:59,280 basically what the dust substructure 27 00:01:02,510 --> 00:01:00,570 looks like and what that tells us about 28 00:01:04,549 --> 00:01:02,520 plant information the other thing that I 29 00:01:06,289 --> 00:01:04,559 want to talk about is how the planetary 30 00:01:08,480 --> 00:01:06,299 initial conditions and that includes all 31 00:01:11,000 --> 00:01:08,490 the chemical conditions are set by the 32 00:01:13,399 --> 00:01:11,010 conditions in the protoplanetary disk so 33 00:01:16,460 --> 00:01:13,409 all the chemistry all the the chemicals 34 00:01:18,590 --> 00:01:16,470 that end up onto comets that end up into 35 00:01:20,330 --> 00:01:18,600 exoplanet atmospheres etc they're coming 36 00:01:23,060 --> 00:01:20,340 from the disk so the question is really 37 00:01:24,380 --> 00:01:23,070 one of inheritance if you have chemicals 38 00:01:24,890 --> 00:01:24,390 in the diffuse clouds and the dense 39 00:01:27,740 --> 00:01:24,900 clouds 40 00:01:29,899 --> 00:01:27,750 how do those get transmitted through the 41 00:01:32,300 --> 00:01:29,909 disk and into comets and eventually 42 00:01:35,240 --> 00:01:32,310 delivered to planets because we know 43 00:01:38,929 --> 00:01:35,250 that there are things like amino acids 44 00:01:41,510 --> 00:01:38,939 or other more complex species on comets 45 00:01:42,920 --> 00:01:41,520 and we also see complex molecules in the 46 00:01:44,240 --> 00:01:42,930 fused clouds but the question is really 47 00:01:47,240 --> 00:01:44,250 what does that look like in the 48 00:01:49,010 --> 00:01:47,250 intermediate stages and what what's 49 00:01:50,330 --> 00:01:49,020 going on here and what actually gets 50 00:01:52,249 --> 00:01:50,340 incorporated into comets what does that 51 00:01:54,350 --> 00:01:52,259 look like maybe an other exoplanet solar 52 00:01:56,719 --> 00:01:54,360 exoplanet solar systems that we haven't 53 00:01:58,010 --> 00:01:56,729 had a chance to look at yet and the 54 00:01:59,420 --> 00:01:58,020 instrument that I'm going to be talking 55 00:02:01,399 --> 00:01:59,430 about that we're using for most of these 56 00:02:04,190 --> 00:02:01,409 studies is almost so Alma is the atacama 57 00:02:06,679 --> 00:02:04,200 large submillimetre right eye and it's 58 00:02:08,119 --> 00:02:06,689 down in Chile it's in the Atacama Desert 59 00:02:10,790 --> 00:02:08,129 of Chile up in the northern mountains 60 00:02:13,910 --> 00:02:10,800 there it's very high up because we want 61 00:02:15,440 --> 00:02:13,920 low water vapor to allow us to look 62 00:02:18,080 --> 00:02:15,450 using radio frequencies so 63 00:02:20,450 --> 00:02:18,090 millimeter/submillimeter frequencies to 64 00:02:22,490 --> 00:02:20,460 look at these discs that allows us to do 65 00:02:24,770 --> 00:02:22,500 two things one is by looking in the 66 00:02:26,330 --> 00:02:24,780 millimeter we're probing dust grains 67 00:02:28,400 --> 00:02:26,340 that are approximately a millimeter in 68 00:02:29,720 --> 00:02:28,410 size so these are little tiny dust 69 00:02:31,490 --> 00:02:29,730 grains that are floating around that are 70 00:02:34,160 --> 00:02:31,500 eventually going to Co s coalesce and 71 00:02:36,410 --> 00:02:34,170 form planets the other thing that we can 72 00:02:38,060 --> 00:02:36,420 do is that molecules emit in the 73 00:02:40,460 --> 00:02:38,070 millimeter and centimeter frequencies 74 00:02:42,200 --> 00:02:40,470 using a rotational spectroscopy so we 75 00:02:43,640 --> 00:02:42,210 can use a rotational spectroscopy to 76 00:02:45,650 --> 00:02:43,650 look for these molecules and see their 77 00:02:48,380 --> 00:02:45,660 signatures and fingerprint them so that 78 00:02:51,410 --> 00:02:48,390 we know what's present in these discs so 79 00:02:52,880 --> 00:02:51,420 as Sonny mentioned Alma is completely 80 00:02:54,890 --> 00:02:52,890 revolutionising our understanding of 81 00:02:56,840 --> 00:02:54,900 protoplanetary discs so this is a really 82 00:02:58,970 --> 00:02:56,850 simple cartoon of what such a disc would 83 00:03:00,290 --> 00:02:58,980 look like this is like an edge on view 84 00:03:01,730 --> 00:03:00,300 and this is a top-down view that's this 85 00:03:04,070 --> 00:03:01,740 is what we used to think was going on 86 00:03:06,950 --> 00:03:04,080 because these were observations from say 87 00:03:09,500 --> 00:03:06,960 the sub as small sorry 88 00:03:11,420 --> 00:03:09,510 it's a millimeter array in Hawaii the 89 00:03:14,660 --> 00:03:11,430 SMA which is kind of like a precursor to 90 00:03:16,160 --> 00:03:14,670 Alma so these were originally the images 91 00:03:17,290 --> 00:03:16,170 of what we thought was going on we 92 00:03:20,450 --> 00:03:17,300 thought that these disks were quite 93 00:03:22,820 --> 00:03:20,460 basically full completely filled in with 94 00:03:24,010 --> 00:03:22,830 dust and then a flared kind of gas disc 95 00:03:27,200 --> 00:03:24,020 around it 96 00:03:28,820 --> 00:03:27,210 however Alma you can see that the beam 97 00:03:30,920 --> 00:03:28,830 size here has this is like our 98 00:03:33,560 --> 00:03:30,930 resolution element has gone from this 99 00:03:35,390 --> 00:03:33,570 large beam to this absolutely tiny beam 100 00:03:38,330 --> 00:03:35,400 Alma has completely blown this out of 101 00:03:40,610 --> 00:03:38,340 the water so now we can see that we're 102 00:03:42,650 --> 00:03:40,620 originally we had no idea that there 103 00:03:44,870 --> 00:03:42,660 were all those rings now we can see all 104 00:03:47,450 --> 00:03:44,880 of these nested rings in both disks like 105 00:03:48,800 --> 00:03:47,460 HL tau and TW Hydra and we know that 106 00:03:50,840 --> 00:03:48,810 there's all this substructure in the 107 00:03:52,550 --> 00:03:50,850 disk so I'm going to talk about a new 108 00:03:54,080 --> 00:03:52,560 disk in which we've seen some of the 109 00:03:55,480 --> 00:03:54,090 substructure and what we might take away 110 00:03:57,770 --> 00:03:55,490 from that in terms of what's causing 111 00:03:59,360 --> 00:03:57,780 these gaps so there's going to be a talk 112 00:04:00,770 --> 00:03:59,370 later talking about how magnetic fields 113 00:04:02,690 --> 00:04:00,780 might play into that and there's a lot 114 00:04:04,190 --> 00:04:02,700 of possibilities as to what's going on 115 00:04:05,630 --> 00:04:04,200 with this but one thing that's been 116 00:04:07,430 --> 00:04:05,640 proposed and it was thought about for a 117 00:04:09,740 --> 00:04:07,440 long time before we actually observed it 118 00:04:12,050 --> 00:04:09,750 with Alma is that planets as they go 119 00:04:13,850 --> 00:04:12,060 around they're going to basically shift 120 00:04:15,710 --> 00:04:13,860 the dust around kind of like blow it out 121 00:04:17,150 --> 00:04:15,720 of the way and suck it in where they 122 00:04:18,500 --> 00:04:17,160 have gravitational pull on it and 123 00:04:21,050 --> 00:04:18,510 they're going to cause pressure traps 124 00:04:24,380 --> 00:04:21,060 that basically carve out these gaps and 125 00:04:26,240 --> 00:04:24,390 rings in the disk so I'm going to talk 126 00:04:27,180 --> 00:04:26,250 about this object a itaú which is a 127 00:04:28,830 --> 00:04:27,190 pretty unique 128 00:04:31,710 --> 00:04:28,840 that's been studied for a long time 129 00:04:33,240 --> 00:04:31,720 since the early 90s and one of the 130 00:04:35,820 --> 00:04:33,250 things that we look at when we look at 131 00:04:38,130 --> 00:04:35,830 stars is we're trying to understand not 132 00:04:39,540 --> 00:04:38,140 only what the properties of the star are 133 00:04:40,710 --> 00:04:39,550 but what are those properties look like 134 00:04:43,830 --> 00:04:40,720 as a function of time 135 00:04:45,450 --> 00:04:43,840 so what we do is we measure the the 136 00:04:47,460 --> 00:04:45,460 brightness of the star as a function of 137 00:04:48,900 --> 00:04:47,470 time and that tells us something about 138 00:04:50,820 --> 00:04:48,910 what's going on so this is used for the 139 00:04:52,800 --> 00:04:50,830 transit method of detecting exoplanets 140 00:04:54,420 --> 00:04:52,810 but it's also used to find a bunch of 141 00:04:57,900 --> 00:04:54,430 other features about what's going on 142 00:05:00,390 --> 00:04:57,910 with the star its magnetic field etc and 143 00:05:01,740 --> 00:05:00,400 so people were monitoring a tile back in 144 00:05:04,200 --> 00:05:01,750 the 90s and they notice that it had this 145 00:05:05,820 --> 00:05:04,210 weird short-term variability and they've 146 00:05:08,670 --> 00:05:05,830 also noticed more recently that it has a 147 00:05:09,750 --> 00:05:08,680 weird long-term dimming trend so I'm 148 00:05:12,030 --> 00:05:09,760 going to talk a little bit more about 149 00:05:14,040 --> 00:05:12,040 those later but right now the the kind 150 00:05:15,720 --> 00:05:14,050 of takeaway to start with is that people 151 00:05:18,480 --> 00:05:15,730 thought the short-term variability was 152 00:05:20,250 --> 00:05:18,490 caused by a highly inclined disc so that 153 00:05:21,830 --> 00:05:20,260 means that it's geometry when you're 154 00:05:24,510 --> 00:05:21,840 looking at it is that it's quite edge on 155 00:05:26,550 --> 00:05:24,520 and that it had this little warp in the 156 00:05:28,530 --> 00:05:26,560 center and that were piz basically 157 00:05:31,410 --> 00:05:28,540 blocking out the light that's coming 158 00:05:33,330 --> 00:05:31,420 that's that you're looking at from the 159 00:05:34,770 --> 00:05:33,340 center of the star there and that goes 160 00:05:36,300 --> 00:05:34,780 as a function of time as it rotates 161 00:05:39,240 --> 00:05:36,310 around and that's causing these little 162 00:05:40,980 --> 00:05:39,250 dips so for right now the takeaway is 163 00:05:44,070 --> 00:05:40,990 that a a tail was thought to be really 164 00:05:46,260 --> 00:05:44,080 edged on but when we started looking at 165 00:05:48,420 --> 00:05:46,270 with Alma it's clearly not edged on it's 166 00:05:50,400 --> 00:05:48,430 a inclined at about like 60 degrees so 167 00:05:53,460 --> 00:05:50,410 that's much more like this rather than 168 00:05:57,000 --> 00:05:53,470 edge-on and it's got weird features so 169 00:05:58,740 --> 00:05:57,010 just like HL tau and T do Hydra it's got 170 00:06:01,680 --> 00:05:58,750 things like this weird little flux 171 00:06:03,840 --> 00:06:01,690 bridge it's got rings here so there's 172 00:06:05,220 --> 00:06:03,850 one ring there another ring bear the 173 00:06:06,270 --> 00:06:05,230 third one's a little hard to see but you 174 00:06:08,670 --> 00:06:06,280 can see it better when I put some 175 00:06:10,260 --> 00:06:08,680 contours on it and so now you can see 176 00:06:12,090 --> 00:06:10,270 that there's there's all these rings in 177 00:06:13,710 --> 00:06:12,100 the disk which are just like HL tau and 178 00:06:15,870 --> 00:06:13,720 tau Hydra where we think that these 179 00:06:18,750 --> 00:06:15,880 might be caused by planets carving out 180 00:06:20,370 --> 00:06:18,760 those those gaps um the other thing that 181 00:06:21,750 --> 00:06:20,380 you might notice is with these contours 182 00:06:24,360 --> 00:06:21,760 you can see that it's kind of twisted in 183 00:06:26,010 --> 00:06:24,370 the center it's got that slight twist to 184 00:06:28,770 --> 00:06:26,020 it I'll come back to that as to a 185 00:06:32,820 --> 00:06:28,780 feature that we think might be involved 186 00:06:34,740 --> 00:06:32,830 with a feature with exoplanets so we 187 00:06:36,210 --> 00:06:34,750 took this data and we tried to reproduce 188 00:06:37,290 --> 00:06:36,220 it with some simple models the first 189 00:06:39,570 --> 00:06:37,300 thing we tried is basically just a 190 00:06:41,100 --> 00:06:39,580 series of concentric rings and that 191 00:06:42,780 --> 00:06:41,110 reproduces the observations really 192 00:06:44,760 --> 00:06:42,790 well the observations are in black here 193 00:06:48,000 --> 00:06:44,770 with the red dashed lines being our 194 00:06:50,940 --> 00:06:48,010 model so it fits it quite well but 195 00:06:52,890 --> 00:06:50,950 there's systemic residuals left over and 196 00:06:54,570 --> 00:06:52,900 those residuals are negative on either 197 00:06:56,880 --> 00:06:54,580 side here and positive on either side 198 00:07:00,920 --> 00:06:56,890 there and so that kind of checkerboard 199 00:07:03,210 --> 00:07:00,930 pattern we think might be caused by a 200 00:07:05,820 --> 00:07:03,220 warp in the disk and I'll get to that in 201 00:07:09,570 --> 00:07:05,830 just a second but for right now we know 202 00:07:11,010 --> 00:07:09,580 that by using this simple model we can 203 00:07:14,190 --> 00:07:11,020 show that there are rings in the disk 204 00:07:16,230 --> 00:07:14,200 and like I was talking about before 205 00:07:18,830 --> 00:07:16,240 there's rings in all these other discs 206 00:07:22,080 --> 00:07:18,840 and almost starting to show that I 207 00:07:24,840 --> 00:07:22,090 there's a whole class of objects at the 208 00:07:26,220 --> 00:07:24,850 substructure disks and all these 209 00:07:30,420 --> 00:07:26,230 substructure disks are showing evidence 210 00:07:32,760 --> 00:07:30,430 for EXO planet formation directly now 211 00:07:35,940 --> 00:07:32,770 going back to that slight twist in the 212 00:07:38,130 --> 00:07:35,950 center what we think might be going on 213 00:07:39,450 --> 00:07:38,140 here is if I kind of put up a schematic 214 00:07:41,970 --> 00:07:39,460 of what we think the system looks like 215 00:07:43,410 --> 00:07:41,980 so there's three rings there's the star 216 00:07:45,900 --> 00:07:43,420 in the center the stars align at about 217 00:07:48,360 --> 00:07:45,910 60 degrees and the Rings are at 60 if 218 00:07:50,550 --> 00:07:48,370 you guys degrees there and we're looking 219 00:07:52,190 --> 00:07:50,560 at it like this so that's what we think 220 00:07:56,660 --> 00:07:52,200 you know schematically it looks like 221 00:07:59,190 --> 00:07:56,670 however we know that because we see that 222 00:08:00,870 --> 00:07:59,200 variability that I mentioned earlier we 223 00:08:03,600 --> 00:08:00,880 know that the inner disk has to be close 224 00:08:06,540 --> 00:08:03,610 to edge on and the other thing that we 225 00:08:08,250 --> 00:08:06,550 know is that there are polar outflows 226 00:08:09,270 --> 00:08:08,260 that come out of the the Jets here I 227 00:08:11,130 --> 00:08:09,280 don't have an image over here but 228 00:08:13,350 --> 00:08:11,140 they're jets that come out and we know 229 00:08:15,870 --> 00:08:13,360 that those are anti aligned with the 230 00:08:17,430 --> 00:08:15,880 disk so rather than being whether the 231 00:08:19,050 --> 00:08:17,440 axis of the star being like this the 232 00:08:21,180 --> 00:08:19,060 axis of the star is actually aligned 233 00:08:23,280 --> 00:08:21,190 this way so this means that the inner 234 00:08:26,910 --> 00:08:23,290 disk and the outer disk are actually 235 00:08:28,980 --> 00:08:26,920 misaligned furthermore it might be 236 00:08:30,360 --> 00:08:28,990 possible that you're getting material 237 00:08:33,270 --> 00:08:30,370 that's streaming across from this 238 00:08:35,610 --> 00:08:33,280 innermost ring here and streaming across 239 00:08:38,760 --> 00:08:35,620 the gap into the star so that might be 240 00:08:43,170 --> 00:08:38,770 associated with that inner flux bridge 241 00:08:45,300 --> 00:08:43,180 as that those radial flows are moving 242 00:08:47,310 --> 00:08:45,310 around the disk then that might be 243 00:08:49,710 --> 00:08:47,320 causing this this flux bridge here now 244 00:08:51,780 --> 00:08:49,720 that's interesting because there are two 245 00:08:54,780 --> 00:08:51,790 features that this might explain so 246 00:08:56,310 --> 00:08:54,790 first of all we know that these stars 247 00:08:58,020 --> 00:08:56,320 signatures of accretion so that's 248 00:08:59,820 --> 00:08:58,030 basically where material is coming on to 249 00:09:02,550 --> 00:08:59,830 the star and feeding the star as it's 250 00:09:03,960 --> 00:09:02,560 being formed that's that's well observed 251 00:09:06,120 --> 00:09:03,970 that a lot of these stars that are in 252 00:09:09,210 --> 00:09:06,130 the disk stage still show signatures of 253 00:09:11,280 --> 00:09:09,220 accretion but if you have these gaps in 254 00:09:14,220 --> 00:09:11,290 the disk material needs to be crossing 255 00:09:16,050 --> 00:09:14,230 those gaps in order to get on to the 256 00:09:18,240 --> 00:09:16,060 star and that's a problem because the 257 00:09:21,120 --> 00:09:18,250 way that these these gaps work is there 258 00:09:23,340 --> 00:09:21,130 pressure traps so you basically got a 259 00:09:24,780 --> 00:09:23,350 gap of pressure and then everything's 260 00:09:26,520 --> 00:09:24,790 kind of pushed up on one side here and 261 00:09:28,230 --> 00:09:26,530 pushed up on the other side so to get 262 00:09:30,420 --> 00:09:28,240 material across that it requires a lot 263 00:09:32,220 --> 00:09:30,430 of energy or an instability in the disk 264 00:09:33,570 --> 00:09:32,230 and that's what we think is going on is 265 00:09:36,060 --> 00:09:33,580 that there's an instability in that 266 00:09:38,400 --> 00:09:36,070 region in between the innermost ring and 267 00:09:40,200 --> 00:09:38,410 the inner disk there must be some sort 268 00:09:42,240 --> 00:09:40,210 of instability here and that instability 269 00:09:44,040 --> 00:09:42,250 can actually be caused by planets so 270 00:09:45,870 --> 00:09:44,050 planets both carve out the gaps but they 271 00:09:47,730 --> 00:09:45,880 can also cause slight instabilities that 272 00:09:50,040 --> 00:09:47,740 allow material to stream across and 273 00:09:51,840 --> 00:09:50,050 solve the problem so this is indirect 274 00:09:54,990 --> 00:09:51,850 evidence for plant information directly 275 00:10:00,540 --> 00:09:55,000 in this disc the other thing that this 276 00:10:02,460 --> 00:10:00,550 is quite interesting for is that this 277 00:10:05,640 --> 00:10:02,470 material that's coming across as it 278 00:10:07,140 --> 00:10:05,650 comes across there it's going to go 279 00:10:09,540 --> 00:10:07,150 across the line of sight that we're 280 00:10:11,250 --> 00:10:09,550 observing so as it comes across the line 281 00:10:13,800 --> 00:10:11,260 of sight it may block out some of that 282 00:10:15,300 --> 00:10:13,810 Starlight this is thick dust so imagine 283 00:10:17,040 --> 00:10:15,310 like looking through a cloud of dust 284 00:10:18,600 --> 00:10:17,050 it's going to block out quite a bit of 285 00:10:21,750 --> 00:10:18,610 light and that might be what's causing 286 00:10:23,550 --> 00:10:21,760 this long-term dimming trend the other 287 00:10:26,520 --> 00:10:23,560 thing that's kind of interesting about 288 00:10:29,760 --> 00:10:26,530 this is okay so you see this this set up 289 00:10:31,860 --> 00:10:29,770 where we've got the disc that's aligned 290 00:10:33,720 --> 00:10:31,870 this way and that's fine because it 291 00:10:35,880 --> 00:10:33,730 doesn't really matter what alignment the 292 00:10:38,220 --> 00:10:35,890 system has relative to us because it can 293 00:10:39,510 --> 00:10:38,230 be you know all 360 degrees it doesn't 294 00:10:41,490 --> 00:10:39,520 matter for the purposes of planet 295 00:10:43,290 --> 00:10:41,500 formation what is interesting though is 296 00:10:45,660 --> 00:10:43,300 that the inner disc and the outer discs 297 00:10:46,890 --> 00:10:45,670 are misaligned and that plays a big role 298 00:10:49,320 --> 00:10:46,900 in planet formation 299 00:10:52,710 --> 00:10:49,330 one of the main observations from the 300 00:10:55,110 --> 00:10:52,720 Kepler project is that they're seeing 301 00:10:57,540 --> 00:10:55,120 one thousands of planets but - they're 302 00:10:59,550 --> 00:10:57,550 seeing that these planets I don't 303 00:11:01,830 --> 00:10:59,560 necessarily always mesh up with radial 304 00:11:03,470 --> 00:11:01,840 velocity measurements so radial velocity 305 00:11:05,970 --> 00:11:03,480 measurements are where rather than 306 00:11:08,290 --> 00:11:05,980 watching the the transit signatures as a 307 00:11:10,570 --> 00:11:08,300 planet goes across in front of the star 308 00:11:12,250 --> 00:11:10,580 you might see signatures of the wobble 309 00:11:14,590 --> 00:11:12,260 of the stars of Planet tugs on it 310 00:11:16,330 --> 00:11:14,600 so from radial velocity signatures we 311 00:11:18,640 --> 00:11:16,340 sometimes see evidence of large outer 312 00:11:21,460 --> 00:11:18,650 planets that are misaligned with the 313 00:11:23,080 --> 00:11:21,470 planets closer in towards the star so if 314 00:11:25,570 --> 00:11:23,090 you want to compare this to say our 315 00:11:27,460 --> 00:11:25,580 solar system the size here is you know 316 00:11:29,290 --> 00:11:27,470 not scale but the size here would be 317 00:11:31,420 --> 00:11:29,300 that this would be our stunt our Sun and 318 00:11:32,860 --> 00:11:31,430 then all of the interests reapply odds 319 00:11:34,870 --> 00:11:32,870 would be inside of this inner disk it's 320 00:11:37,030 --> 00:11:34,880 it's quite small only a few au in size 321 00:11:38,770 --> 00:11:37,040 and then maybe Jupiter will be about 322 00:11:39,970 --> 00:11:38,780 here Saturn will be out here and the 323 00:11:41,140 --> 00:11:39,980 Oort cloud will be out here in the 324 00:11:44,470 --> 00:11:41,150 Kuiper belt New York cloud would be out 325 00:11:47,560 --> 00:11:44,480 here so this means that basically you 326 00:11:49,150 --> 00:11:47,570 could easily have a giant outer planet 327 00:11:51,130 --> 00:11:49,160 here that's misaligned with the 328 00:11:52,780 --> 00:11:51,140 terrestrial planets and our solar system 329 00:11:53,950 --> 00:11:52,790 they're all aligned but Kepler seeing 330 00:11:56,350 --> 00:11:53,960 that there are a lot of systems where 331 00:11:57,850 --> 00:11:56,360 these are misaligned so directly having 332 00:11:59,500 --> 00:11:57,860 evidence for this sort of misaligned 333 00:12:00,970 --> 00:11:59,510 system kind of fills in some of our 334 00:12:03,330 --> 00:12:00,980 missing pieces as to how would those 335 00:12:05,230 --> 00:12:03,340 systems in Kepler actually be formed and 336 00:12:08,350 --> 00:12:05,240 we're going to be able to test this 337 00:12:10,120 --> 00:12:08,360 directly with new observations in the 338 00:12:12,340 --> 00:12:10,130 future where we're actually able to go 339 00:12:14,470 --> 00:12:12,350 even higher resolution more comparable 340 00:12:16,150 --> 00:12:14,480 to those hl2 observations and we should 341 00:12:18,610 --> 00:12:16,160 be able to see whether this is actually 342 00:12:20,680 --> 00:12:18,620 going on or not the other thing that I 343 00:12:22,480 --> 00:12:20,690 want to just briefly touch on is I 344 00:12:25,060 --> 00:12:22,490 mentioned that not only are we looking 345 00:12:26,200 --> 00:12:25,070 at the planet formation in the discs but 346 00:12:27,970 --> 00:12:26,210 we're also trying to figure out the 347 00:12:29,500 --> 00:12:27,980 chemistry that's going into these 348 00:12:32,320 --> 00:12:29,510 planets into these comets that are 349 00:12:33,880 --> 00:12:32,330 forming and for all of the you know 350 00:12:35,530 --> 00:12:33,890 chemists and biologists in the audience 351 00:12:37,300 --> 00:12:35,540 these aren't complex molecules for you 352 00:12:40,600 --> 00:12:37,310 guys but for our purposes they are 353 00:12:42,760 --> 00:12:40,610 because a stellar radiation interstellar 354 00:12:43,360 --> 00:12:42,770 radiation it'll blast apart molecules no 355 00:12:46,690 --> 00:12:43,370 problem 356 00:12:48,730 --> 00:12:46,700 so I most of the molecules that we see 357 00:12:49,930 --> 00:12:48,740 in space are quite small compared to 358 00:12:53,110 --> 00:12:49,940 what you guys are used to working with 359 00:12:54,880 --> 00:12:53,120 and for our purposes methyl methyl and 360 00:12:56,470 --> 00:12:54,890 methyl cyanide are kind of the the first 361 00:12:58,720 --> 00:12:56,480 building blocks for being able to form 362 00:13:00,340 --> 00:12:58,730 more complex species so it's really 363 00:13:02,080 --> 00:13:00,350 important to be able to trace these and 364 00:13:06,190 --> 00:13:02,090 see how do they get incorporated into 365 00:13:08,260 --> 00:13:06,200 comets and very recently we put out two 366 00:13:10,000 --> 00:13:08,270 papers that showed for the first time at 367 00:13:11,770 --> 00:13:10,010 a detection of both methanol and our 368 00:13:13,960 --> 00:13:11,780 detection of methyl cyanide now the 369 00:13:15,730 --> 00:13:13,970 problem here is so these contours are 370 00:13:18,070 --> 00:13:15,740 only one and a half sigma contours so 371 00:13:20,260 --> 00:13:18,080 these are quite weak detection zhh and 372 00:13:21,910 --> 00:13:20,270 the problem is that basically as you go 373 00:13:24,129 --> 00:13:21,920 up in complexity with MA 374 00:13:26,199 --> 00:13:24,139 heels in in space you get fewer and 375 00:13:27,759 --> 00:13:26,209 fewer of them which makes sense but that 376 00:13:29,319 --> 00:13:27,769 means that as you go to more complex 377 00:13:30,579 --> 00:13:29,329 species they're going to get weaker and 378 00:13:32,470 --> 00:13:30,589 weaker and we're not going to be able to 379 00:13:35,110 --> 00:13:32,480 see their their signatures as strongly 380 00:13:36,610 --> 00:13:35,120 so to be able to investigate complex 381 00:13:38,230 --> 00:13:36,620 chemistry and protoplanetary discs is 382 00:13:40,509 --> 00:13:38,240 going to require us to probe much much 383 00:13:43,000 --> 00:13:40,519 deeper use up more telescope time which 384 00:13:45,069 --> 00:13:43,010 is expensive etc so something that I've 385 00:13:46,870 --> 00:13:45,079 been working on is a new method to pull 386 00:13:48,430 --> 00:13:46,880 out these signals with higher 387 00:13:50,079 --> 00:13:48,440 signal-to-noise so if you're familiar 388 00:13:51,699 --> 00:13:50,089 with radar one of the things that they 389 00:13:53,079 --> 00:13:51,709 use is something called match filtering 390 00:13:54,550 --> 00:13:53,089 where basically if you know what your 391 00:13:56,019 --> 00:13:54,560 signal looks like you can convolve it 392 00:13:59,560 --> 00:13:56,029 through the data and get out and improve 393 00:14:01,840 --> 00:13:59,570 the spectrum so we've used this for our 394 00:14:03,340 --> 00:14:01,850 data so these were the observations of 395 00:14:04,870 --> 00:14:03,350 the methanol that I showed so these were 396 00:14:07,000 --> 00:14:04,880 the individual lines there they're very 397 00:14:08,769 --> 00:14:07,010 very weakly detected less than 3 Sigma 398 00:14:11,199 --> 00:14:08,779 for each of these and it's just barely 399 00:14:12,670 --> 00:14:11,209 detected in the stack spectrum but when 400 00:14:14,319 --> 00:14:12,680 we applied the match filter to it 401 00:14:16,720 --> 00:14:14,329 we get strong detections of each of the 402 00:14:20,500 --> 00:14:16,730 individual lines and it's over seven 403 00:14:22,180 --> 00:14:20,510 segment detection of the stack lines so 404 00:14:23,800 --> 00:14:22,190 that was roughly a 45 percent 405 00:14:25,360 --> 00:14:23,810 signal-to-noise boost which sounds like 406 00:14:27,340 --> 00:14:25,370 maybe a little bit but it's not too much 407 00:14:29,230 --> 00:14:27,350 but that actually translates to a factor 408 00:14:30,970 --> 00:14:29,240 of over two and observing time so we 409 00:14:32,740 --> 00:14:30,980 actually save a lot of telescope time by 410 00:14:33,939 --> 00:14:32,750 by using this method and I'm pretty 411 00:14:35,380 --> 00:14:33,949 excited we're going to be able to apply 412 00:14:36,880 --> 00:14:35,390 this to a couple other studies in the 413 00:14:39,130 --> 00:14:36,890 future and one thing that we're really 414 00:14:41,710 --> 00:14:39,140 hoping to do is apply it to spectral 415 00:14:43,420 --> 00:14:41,720 lines surveys where we can start to look 416 00:14:45,160 --> 00:14:43,430 for all sorts of different lines of 417 00:14:46,990 --> 00:14:45,170 complex species and look for ones that 418 00:14:48,819 --> 00:14:47,000 we might not have thought would be there 419 00:14:50,560 --> 00:14:48,829 in the first place already from one of 420 00:14:53,050 --> 00:14:50,570 these surveys we have five new molecular 421 00:14:56,350 --> 00:14:53,060 detection x' in that survey so just as a 422 00:14:58,240 --> 00:14:56,360 takeaways from this I using Alma 423 00:15:00,939 --> 00:14:58,250 we're basically probing two aspects of 424 00:15:02,800 --> 00:15:00,949 planet formation and comet formation one 425 00:15:04,750 --> 00:15:02,810 is we're actually probing directly what 426 00:15:06,040 --> 00:15:04,760 structure the disk looks like we saw 427 00:15:07,630 --> 00:15:06,050 that for a a Tau that it's a 428 00:15:10,090 --> 00:15:07,640 substructure disk that has those rings 429 00:15:12,040 --> 00:15:10,100 and gaps with direct evidence for planet 430 00:15:14,139 --> 00:15:12,050 formation and it's got this warp the 431 00:15:16,809 --> 00:15:14,149 warp might explain misaligned exoplanet 432 00:15:18,790 --> 00:15:16,819 systems and we're also starting to use 433 00:15:21,819 --> 00:15:18,800 Alma to find complex molecules and disks 434 00:15:24,759 --> 00:15:21,829 which proves that they're abundant 435 00:15:27,129 --> 00:15:24,769 during the processes of planet and kamek 436 00:15:29,500 --> 00:15:27,139 formation and so that means that they 437 00:15:32,259 --> 00:15:29,510 might be delivered from those comets on 438 00:15:33,639 --> 00:15:32,269 two planets in the future and then 439 00:15:35,710 --> 00:15:33,649 they're usable for all of you guys in 440 00:15:49,990 --> 00:15:35,720 all the other studies that you're doing 441 00:15:52,660 --> 00:15:50,000 so that's it questions I was just 442 00:15:54,340 --> 00:15:52,670 wondering do many hypotheses about how 443 00:15:55,150 --> 00:15:54,350 you actually get those warps how you get 444 00:15:57,370 --> 00:15:55,160 the misaligned 445 00:15:59,800 --> 00:15:57,380 discs yeah there's a couple different 446 00:16:01,810 --> 00:15:59,810 things that might be going on I ate 447 00:16:03,790 --> 00:16:01,820 house a little bit weird in this respect 448 00:16:06,060 --> 00:16:03,800 actually because it's quite easy to form 449 00:16:08,290 --> 00:16:06,070 those warps if you have a binary star 450 00:16:09,940 --> 00:16:08,300 and that's been theorized before that 451 00:16:12,820 --> 00:16:09,950 binary stars can basically cause torques 452 00:16:14,050 --> 00:16:12,830 that would allow that to happen it's a 453 00:16:16,750 --> 00:16:14,060 little bit harder to do that with a 454 00:16:18,610 --> 00:16:16,760 single star system like a Tau but 455 00:16:20,620 --> 00:16:18,620 there's a couple different mechanisms 456 00:16:21,940 --> 00:16:20,630 that that might be able to work and 457 00:16:24,400 --> 00:16:21,950 there's a few groups that are trying to 458 00:16:25,810 --> 00:16:24,410 do theory on that right now so maybe in 459 00:16:27,340 --> 00:16:25,820 about half a year we should have an 460 00:16:30,610 --> 00:16:27,350 answer for that but there are groups 461 00:16:32,920 --> 00:16:30,620 that are working on that Thanks okay 462 00:16:34,210 --> 00:16:32,930 this is a total hypothetical I'm not 463 00:16:36,070 --> 00:16:34,220 sure if you even know the answer right 464 00:16:37,930 --> 00:16:36,080 off the top of your head but um so 465 00:16:40,300 --> 00:16:37,940 obviously within this line disk you're 466 00:16:41,800 --> 00:16:40,310 gonna have a change in the way that the 467 00:16:43,030 --> 00:16:41,810 star light is able to illuminate the 468 00:16:45,100 --> 00:16:43,040 rest of the disk mm-hmm 469 00:16:47,350 --> 00:16:45,110 how do you expect that would affect like 470 00:16:48,760 --> 00:16:47,360 what chemical species can form in the 471 00:16:50,680 --> 00:16:48,770 parts of the disc that are misaligned 472 00:16:54,430 --> 00:16:50,690 with that yet index Center that's a 473 00:16:57,190 --> 00:16:54,440 great question actually um so for one 474 00:16:59,050 --> 00:16:57,200 thing on the the misaligned inner disc 475 00:17:00,940 --> 00:16:59,060 is going to process and so that's going 476 00:17:03,580 --> 00:17:00,950 to process on timescales of maybe like 477 00:17:06,640 --> 00:17:03,590 decades or so so it's not going to have 478 00:17:08,439 --> 00:17:06,650 a huge impact on say if a comet is 479 00:17:10,300 --> 00:17:08,449 forming at this distance versus that 480 00:17:12,819 --> 00:17:10,310 distance it's not going to totally 481 00:17:14,410 --> 00:17:12,829 change the cometary composition what can 482 00:17:15,790 --> 00:17:14,420 happen though is that shadowing will 483 00:17:16,990 --> 00:17:15,800 cause temperature differences in the 484 00:17:19,480 --> 00:17:17,000 disk which can't affect the chemistry 485 00:17:21,880 --> 00:17:19,490 dramatically and that also gives me a 486 00:17:24,490 --> 00:17:21,890 chance to talk about a new result that 487 00:17:25,569 --> 00:17:24,500 that our group has where we're looking 488 00:17:28,240 --> 00:17:25,579 at something slightly different with 489 00:17:30,930 --> 00:17:28,250 flares so a lot of these stars flare 490 00:17:33,460 --> 00:17:30,940 quite frequently in the x-ray and flares 491 00:17:34,660 --> 00:17:33,470 which also can be affected by shadowing 492 00:17:37,870 --> 00:17:34,670 and things like that can dramatically 493 00:17:39,670 --> 00:17:37,880 change the the chemical composition of 494 00:17:41,350 --> 00:17:39,680 the disc because those flares can 495 00:17:43,870 --> 00:17:41,360 radiate things and completely change 496 00:17:46,510 --> 00:17:43,880 them and that might also affect things 497 00:17:48,550 --> 00:17:46,520 like say amino acid stability on comets 498 00:17:49,420 --> 00:17:48,560 right because these flares can vary 499 00:17:51,010 --> 00:17:49,430 dramatically 500 00:17:56,680 --> 00:17:51,020 affect the chemistry and there and 501 00:17:58,870 --> 00:17:56,690 destroy more complex species so just you 502 00:18:01,270 --> 00:17:58,880 mentioned that you can study rotation of 503 00:18:05,170 --> 00:18:01,280 molecules with these radio telescopes 504 00:18:08,110 --> 00:18:05,180 right so is that due to redshift if yes 505 00:18:11,680 --> 00:18:08,120 can you study vibrational transitions 506 00:18:14,470 --> 00:18:11,690 electronic and if yes what's the reason 507 00:18:17,350 --> 00:18:14,480 to use other techniques to basically 508 00:18:19,870 --> 00:18:17,360 detect molecules yes radio telescopes 509 00:18:22,740 --> 00:18:19,880 are cheaper yes so um there's a couple 510 00:18:25,480 --> 00:18:22,750 different things there so first we use 511 00:18:27,940 --> 00:18:25,490 radio telescopes they are a lot cheaper 512 00:18:29,560 --> 00:18:27,950 in some respects because you can use 513 00:18:30,520 --> 00:18:29,570 radio telescopes on the ground because 514 00:18:33,550 --> 00:18:30,530 they're not as affected by the 515 00:18:36,850 --> 00:18:33,560 atmosphere infrared telescopes and other 516 00:18:39,790 --> 00:18:36,860 things need to be pushed up into the in 517 00:18:41,460 --> 00:18:39,800 orbit or in space so that's why JWST is 518 00:18:43,800 --> 00:18:41,470 going to be launched into space 519 00:18:46,600 --> 00:18:43,810 rotational spectroscopy can only probe 520 00:18:47,980 --> 00:18:46,610 molecules that are in the gas phase so 521 00:18:50,110 --> 00:18:47,990 that's great for being able to probe 522 00:18:51,790 --> 00:18:50,120 things in kind of the the gas portion of 523 00:18:53,380 --> 00:18:51,800 the disk what that doesn't what that 524 00:18:56,020 --> 00:18:53,390 means is that we aren't able to probe 525 00:19:00,400 --> 00:18:56,030 species that are on grain surfaces so in 526 00:19:02,650 --> 00:19:00,410 the very the kind of middle layer of the 527 00:19:04,000 --> 00:19:02,660 disk these molecules are freezing out 528 00:19:07,060 --> 00:19:04,010 onto grain surfaces and they're going to 529 00:19:08,710 --> 00:19:07,070 be incorporated I into the on from those 530 00:19:10,120 --> 00:19:08,720 grains into comments things like that so 531 00:19:12,070 --> 00:19:10,130 the planet formation zone is actually 532 00:19:13,480 --> 00:19:12,080 mostly frozen out on two-brains and we 533 00:19:15,430 --> 00:19:13,490 can't probe that with rotational 534 00:19:16,990 --> 00:19:15,440 spectroscopy what you might be able to 535 00:19:18,640 --> 00:19:17,000 use you could use vibrational 536 00:19:19,540 --> 00:19:18,650 spectroscopy to probe that but the 537 00:19:21,580 --> 00:19:19,550 problem is that you need to have a 538 00:19:24,010 --> 00:19:21,590 backlit source in order to do that 539 00:19:27,430 --> 00:19:24,020 efficiently so you need to have a way to 540 00:19:29,080 --> 00:19:27,440 illuminate those those icy grains from 541 00:19:31,570 --> 00:19:29,090 behind and the only way to do that is a 542 00:19:33,810 --> 00:19:31,580 very edge on disk and if you have an 543 00:19:37,420 --> 00:19:33,820 extremely edge on disk it may be like 544 00:19:39,310 --> 00:19:37,430 you know 87 degrees inclination or 545 00:19:41,920 --> 00:19:39,320 something it's a very narrow range then 546 00:19:43,690 --> 00:19:41,930 you could use JWST to to investigate 547 00:19:45,760 --> 00:19:43,700 those eye screens but it's going to 548 00:19:46,690 --> 00:19:45,770 require a very narrow set of parameters 549 00:19:48,130 --> 00:19:46,700 and that's actually one of the reasons 550 00:19:49,300 --> 00:19:48,140 that we originally looked at a a tile 551 00:19:51,100 --> 00:19:49,310 because we knew that it was supposed to 552 00:19:52,780 --> 00:19:51,110 be a John and we were hoping to find a 553 00:19:54,640 --> 00:19:52,790 system that might be able to then be 554 00:19:56,140 --> 00:19:54,650 used for data OST there's a couple other 555 00:20:00,610 --> 00:19:56,150 target systems that might be able to be 556 00:20:01,560 --> 00:20:00,620 used for that I have a question so what 557 00:20:02,910 --> 00:20:01,570 keeps the dust 558 00:20:05,550 --> 00:20:02,920 dreamers from like getting smeared out 559 00:20:07,590 --> 00:20:05,560 like why why is it rotating rigidly yeah 560 00:20:09,480 --> 00:20:07,600 that's a great question um it doesn't 561 00:20:13,830 --> 00:20:09,490 rotate rigidly that was just because I'm 562 00:20:15,300 --> 00:20:13,840 bad at PowerPoint uh and I don't do 563 00:20:17,910 --> 00:20:15,310 hydrodynamic simulations so I don't have 564 00:20:19,680 --> 00:20:17,920 anything pretty to show but in reality 565 00:20:21,570 --> 00:20:19,690 it's more of like a vortex type thing 566 00:20:23,070 --> 00:20:21,580 like I said it's an instability so you 567 00:20:25,650 --> 00:20:23,080 would get all sorts of swirling 568 00:20:28,110 --> 00:20:25,660 streamers but those streamers might be 569 00:20:30,480 --> 00:20:28,120 coherent on timescales of maybe 10 to 20 570 00:20:31,740 --> 00:20:30,490 years so enough to rotate around and 571 00:20:37,710 --> 00:20:31,750 basically cause the features that we're 572 00:20:38,970 --> 00:20:37,720 seeing so yeah so that yeah so actually 573 00:20:40,770 --> 00:20:38,980 that's that's one thing that we're 574 00:20:42,750 --> 00:20:40,780 starting to see is actually so it looks 575 00:20:44,100 --> 00:20:42,760 like that long term dimming it's 576 00:20:46,320 --> 00:20:44,110 starting to come out of that right now 577 00:20:48,420 --> 00:20:46,330 and if that is happening then it would 578 00:20:50,130 --> 00:20:48,430 basically show that it's it's a one 579 00:20:52,800 --> 00:20:50,140 feature that's moving across the face of 580 00:20:54,000 --> 00:20:52,810 the disk and also with all my 581 00:20:55,260 --> 00:20:54,010 observations with the high-resolution 582 00:20:57,150 --> 00:20:55,270 observations we'll be able to make a 583 00:20:58,800 --> 00:20:57,160 prediction then as to when it would come 584 00:21:00,090 --> 00:20:58,810 back around so we're hoping to be able 585 00:21:02,570 --> 00:21:00,100 to make an actual testable prediction